This invention generally relates to absorbent composites used in disposable articles such as diapers, child's training pants, feminine care articles, incontinence articles, bandages, and the like, and more particularly to such absorbent composites containing a superabsorbent material and methods for making such composites.
Conventional disposable articles typically include an absorbent composite, or absorbent core, conventionally formed by air forming, air laying or other forming technique. For example, the manufacture of such an absorbent composite may begin by fiberizing a fibrous sheet of cellulosic or other suitable material in a conventional fiberizer, or other shredding or comminuting device, to form discrete fibers. In addition, particles or fibers of superabsorbent material, which are water insoluble, water swellable and capable of absorbing up to at least about ten times their weight in 0.9% by weight concentration sodium chloride solution in water, are mixed with the discrete fibers. The fibers and superabsorbent particles are then entrained in an air stream and directed to a foraminous forming surface upon which the fibers and superabsorbent particles are deposited to form an absorbent fibrous web. In addition, bonding agents or other strengthening components may be incorporated to provide a more stabilized web.
Other techniques have also been employed to form absorbent composites. Such techniques have included dry-forming techniques, wet-forming techniques, and foam-forming techniques. The resulting absorbent composites have included absorbent fibers, natural fibers, synthetic fibers, foams, superabsorbent materials, binder materials, and strengthening components in desired combinations. However formed, the absorbent composite may then be stored or immediately directed for further processing (e.g., being cut into individual absorbent composites) and assembly with other components to produce a desired absorbent article.
While such absorbent composites incorporating particulate superabsorbent materials are useful, their absorptive properties may be limited due to the relatively low surface area to mass ratio of the particulate superabsorbent material within the composite. Also, the use of particulate superabsorbent materials is known to cause gel blocking, that is, as the superabsorbent particles swell upon absorbing liquid, it fills the voids within the composite and thereby blocks the flow of fluid within the composite to the superabsorbent particles upon further insults of the composite.